Unloading device for air-compressors.



W. H. WINEMAN.

UNLOADING DEVICE FOR AIR COMPRESSORS. APPLICATION FILED JUNE 14. 1913.

Patented Dec. 4, 1917.

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W H. WINEMAN.

UNLOADING DEVICE FOR MR COMPRESSORS- APPLICATION FILED JUNE 14' 1913Patanted Den 4, 1917.

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WADE HVWINEMAN, OF CHICAGO, ILLINOIS, ASSIGNOR, BY IVLESNE ASSIGNMENTS,7T0

1 SULLIVAN MACHINERY COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION orMASSACHUSETTS.

nnLoAnrive nnvicn roe Ain-conrniissons.

Application filed June 14, 1913. Serial No. 773,745.

To all whom it may concern Be it known that I,

of Chicago, county" of Cook, State of -Tllinois, whose post-ofliceaddress is 5&3? Gladys avenue, Chicago,- Illinois, have invented anImprovement in Unloading Devices for Air Compressors, of which thefollowing do scription, in connection withthe accompa nying drawings, isaspecification, like characters on the drawings representing like parts.i i This invention relates toimprovements in air compressors and moreparticularly to improved means for unloading air compressors. Theinvention will be best understood by reference to the followingdescription when taken in connection with the accompanyingillustrationof onespecific embodiment thereof, while its scope will be moreparticularly pointed out in the appended claims. V

In'the drawings:

Figure 1 is a diagrammatic elevation of" a compressor embodying oneformofthe invention Fig. 2 is a detail showing the air trigger orcontrolling valve for the unloading valve; and

Fig. 3 shows in partial sectionthe unloading and relief valves withconnected mechanism.

Referring to the drawings and to the embodiment of the invention thereselected for illustration, a multiple stage compressor is shown havingthe low pressure cylinder 1,

the high pressure'cylinder 2 and the intercooler 3. The low pressurecylinder has its suction 4 and discharge 5, while the high pressurecylinderhas its suction 6connected to the intercooler and its discharge7 0011- n'ected'to the receiver (the latter not shown) The mainunloading valve 8 (Fig. 3) is i of common construction and is interposedin the suction 4: of the low pressure cylinder. It is moved down atappropriate times to out 'ofl' the suction by means of a piston 9working within the cylinder 10, the spring 11 (Fig. 1) being utilizednormally to elevate the valve. The piston 9 is caused to be depressed bythe action of an air trigger or controlling mechanism shown in detail inFig. 2 and constructed as follows:

Secured to the side of the cylinder 10 near WADE H. WINEMAN, a citizenof the United States, and a residentthe top thereof is the casting 12 inwhich is into the cylinder space 10 above thepistonj 9. This portcommunicates with a pipe 14;

through an orifice 15, the latter being con trolled by the unloadercontrolling valve16.

the receiver, pressure fluid at the receiver pressure flows through thepipe13 to the cylinder 10, depresses the piston 9 and cuts oifd thesuction from the low pressure cyl- 1n er. r

when the valve is elevated, closing the escape orifice 17. When thevalveis depressed, pressure fluid is permitted to escape through the orifice17,- grooves 18 inthe valve, escape chamber 19 and opening 20 to theatmosphere. The valve 16 is normally held on itslower seat closing theorifice 15 by a spring 21'interposed between a of the valve 16 willyliftthe valve against the pressure of the spring 21, allowing air attermlnal pressure to pass through the orifice and the port 13 tothe topof the piston 9. At the same time the controlling valve 16 is liftedagainst itsupper seat, cutting off the atmospheric vent opening 20 fromthe port 13. This acts to unload the low pressure cylinder by depressingthe unloading valve 8 and throttling the low pres sure suction. Theupper seat of the valve 16 is of greater diameter than the lower seat,

so that the valve will continue to be held against its upper seat by thepressure of the The valve 16 has an upper seat of greater diameterthanits lower seat, the upper seat,

- Specifieation of Letters Patent. if Patented DEG. 4L, 1917., l

formed the pressure supply port 13 opening When the valve is lifted, thepipe 14: being connected to the high pressure delivery 7 or air actingfrom beneath until there is a drop in the pressure of the receiver whichis supplied through the pipe 14l or "until an in creased pressure on thevalve stem from above takes place, or until both these conditionsobtain. a i H a Thespace within the cylinder 25 and 'be-"" low thepiston 24 is connected by a pipe 27 with a space.whereinizthere isproduced a vacuumv when the compressor .is unloaded. This connection maybe made to the suc tion side of the low pressure cylinder, but hereinthe pipe 27 is connected" to the space of the intercooler 3 so that whenthe compressor is unloaded and the pressure in the intercooler fallsbelow that of the atmosphere, the piston 24 tends to bedepressed :moreor less by the atmospheric pressureactingthrough theopening 28 in thetop of the cylinder 25. The pressure of the piston therefore is added tothat pfthe spring 21 and when a point is reached where this overbalancesthe receiver pressure on the lower side of the valve .16, the latterwill descend closing the orifice lo and opening.

the port 135to the atmosphere throughthe chamber 17, grooves '18,chamber 19 and passage 20. This releases pressure. fluid from behind thecontrolling piston 9 and the latter is caused to lift through the spring11 and open the throttle and unloading Valve 8, again loading thecompressor.

. When the compressor is loaded the pressure in the intercooler is againraised and the piston 24 is forced up against the set screw 26 by thespring 21, reducing. the pressure against the valve stem to the amountnecessary to hold the valve 16 on its lower seat until the predeterminedpressure is aga nv reached, when the cycle .of operations 1s.

repeatedf Af ter the. vacuum has been produced in the intercooler 3,.thepressure against the piston. 24 is always constant and the resultingtension on the spring may be regulated by the travel of the piston. Toregulate such travel the adjustable set screw 30 is provided in thebottom ofthe cylinder 25.

In order to prevent undue heating in the high pressure'cylinder whichmight follow from compressing'air taken from the intercooler at anabnormally low pressure after the low pressure cylinder has beenunloaded, relief valves 31 are preferably provided for each end of thehigh pressure cylinder. These valve'sare automatically opened when thelowpressure cylinder is unloaded. Each relief'valve (see Fig.3) is ofcylindrical form witha closed end which is pressed toitsseat 33 in thecylinder head by the light spring 32. .The valve is normallymaintaineduponits seat against the inter rial-compression by terminalpressure fluid conveyed .to the interior of the valve 31 by the pipe 34,the-latter being normally connected to the'terminal pressure pipe 14through the valve I chamber and the v branchpipe 36. Under normalconditions,

in'der is unloaded, the valve 37, which is slidably mounted in the valvechamber 35, is moved to out off communication between the pipes 34 and36 and open communication between the pipe 34 and the pipe 38, thelatter opening into the atmosphere.

To provide for'this' automatic movement of the valve, the latter has twopiston heads 39 and 40, the latter of greater diameter than the former.\Vhen the controlling piston 9 for the unloading valve is moved to closethe latter, a part of the pressure fluid admitted to the top of thepiston 9 also passes into the pipe 41 which is connected to the rearofthe cylinder 10 and is carried thereby to the end of the valve piston 40of larger diameter causing the described movement of the valve. Thisconnects the pipe 34 to the atmosphere, placing atmospheric pressure onthe valve 31 so that the latter readily lifts under compression andpermits the escape of the compressed air from the high pressure cylinderthrough the atmospheric vent 42.

So long as the unloading valve 8 remains closed, terminal pressure issupplied through the pipe 41, maintaining the valve 37 in its prescribedposition, wherein the pipe 34 is cut off" from the terminal pressurepipe 36 and opened to the atmospheric pipe 38. hen the unloading valveopens, due to the air trigger mechanism cutting off the supply ofterminal pressure from the top of the cylinder 10 and opening the latterto the atmosphere, the terminal pressure acting through the pipe 36 onthe smaller head 39 of the piston valve 37 moves the latter to theopposite end of the valve chamber and again cuts off the pipe 34 fromthe atmospheric pipe 38 and applies terminal pressure through the pipe34 to the top of the valve 31, forcing the latter to its seat. Whilethis condition is maintained, the valve 37 is held to its seat by theterminal pressure, since the effective area of the valve 31 exposed tothe interior pressure of the compressor is less than the effective areaof the valve exposed to the terminal pressure received through the pipe34. The valve 31 is provided with a partition wall 43 against which thespring .32 seats and which is also adapted to strike an adjustable stopscrew 44 having the hand wheel 45 whereby the lift of the valve may beregulated.

In order that thedischarge of air from the high pressure cylinderthrough the relief valve 31 may nottake place simultaneously with theunloading of the low pressure cylinder, but may be deferred until alarge portion of the air in the intercoolcr has been compressed in thehigh pressure cylinder and delivered to the receiver, its movement ispreferably retarded relatively to that of the unloading valve. Anysuitable means may be provided for effecting this retardation,but hereinI have shown the valve 37 valve 37 andworking in a cylinder 49 filledwith 'oil or other suitable liquid. The opposite ends of the cylinderare connected by a pipe 50 whereby the liquid may be caused to pass fromone end of the cylinder to the other when the piston is moved. Therapidity with which the liquid is transferred from one end ofthecylinder to the other may be controlled by the valve 51 in the pipe50.

It will be observed that the air trigger is provided with an adjustmentboth for loading and unloading. The position of the set screw 26 at thetop of the cylinder determines the unloading pressure while the setscrew 30 at the bottom of the cylinder determines the loading pressure.This permits a wide variation in the adjustment of the apparatus.

While I have herein shown and described for purposes ofillustration onespecific form of the invention, it is to be understood that the same isnot limited to thespecific embodiment herein shown, but that extensivedeviations may be made from the described form without departing fromthe spirit of the invention.

Claims:

1. In an air compressor, the combination with an unloading valve, of acontrolling device therefor provided with means for moving the unloadingvalve, valve means normally closed but adapted to open under apredetermined pressure to admit pressure fluid to move said unloadingvalve moving means, means for holding said valve means closed comprisinga spring, a cylinder with its contained piston, the latter adapted toaugment thepressure of the spring against the closing means, and meansdependent on the unloading of the compressor to vary the pressure onopposite sides of the piston.

2. In a compressor, the combination with an unloading device, of acontrolling device therefor comprising a piston for moving the unloadingvalve, valve means normally closed but adapted to open under apredetermined terminal pressure to admit pressure ing said valve meansclosed comprising a sp'ring,'a cylinder with its containedpiston, thelatter adapted to augment the pressure of the spring against the closingmeans, and a pipe connection between the cylinder and a low pressurespace of the compressor to augment the pressure of the spring after thecompressor has been unloaded.

3. In a compressor, the combination with an unloading valve, of acontrolling device having valve means to control said unloading valve,said valve means being adapted I to move when a predetermined terminalfluid to move said piston, means for holdpressure is reached, and meansfor restoring said valve means dependent on a drop 1n pressure in a lowpressure space of the compressor after the latter has been unloaded.

4. Ina compressor, the combination with an unloading valve, of acontrollingdevice having valve means to control said unloading valve,said valve means being adapted to be moved'when a predetermined terminalpressure is reached, and means for restoring said valve means dependentonthe dropin intercooler pressure after the compressor has beenunloaded. i p

5. In an air compressor, the combination with an unloading valve, ofmeans for moving the same comprising a valve adapted to be moved under apredetermined terminal pressure, aspring for restoring. said valve, andmeans to augment said spring dependent on the drop in pressure of alowpressure space of the compressor following the un loading of thecompressor.

6. In a compressor, the combination with an unloading valve, of acontrolling device therefor including a valve, a sprlngto move thevalve, a piston adapted to compress said spring, a cylinder containingsaid piston, a connection on one side of saidpiston to a low pressurespace of the compressor, and a connection on the opposite side of saidpis tonjto the atmosphere. I p

7. Inacompi'essor, the combination with i an unloading valve, of acontrolling device therefor including a valve, a spring to move thevalve, a piston adapted to compress said spring, a cylinder containingsaid piston, a connection on one side of said piston to a low pressurespace of the compressor, a connection on the opposite side of saidpiston to the atmosphere, and supplemental means for regulating thetravel of said piston.

8. In a compressor, the combination with an unloading valve, of acontrolling device thereforincluding avalve, a spring to move thevalve,a piston adapted to compresssaid spring, a cylinder containing saidpiston, a connection on one side of said piston to a low pressure spaceof the compressor, aconnection on the opposite side ofsaid piston to theatmosphere, andsupplcmental means for regulating the travel of saidpiston in either direction.

t 9. Ina multiple stage compressor, the com bination with anunloadingvalve, of a controlling device therefor including a valve, a spring tomove the valve, a piston adapted to compress said spring, a cylindercontaining said piston, a connection on one side of said piston to theintercooler, and a connection on the opposite side of said piston to theatmosphere.

10. In combination, pumping mechanism, unloading means actuated bypredetermined pressure forcutting off the ingress of air to saidmechanism, a connection between said pumping mechanism and theatmosphere, relief means for said pumping mechanism in said connection,and means between the unloading means and said rellef means for delayingthe operation of the latter.

pressure, of a relief valve for the discharge end, the latter normallyheld to its seat by pressure fluid,.a second valve adapted to lower thepressure fluid on said relief. valve, means dependent on the action ofsaid unloading device for moving said second valve, and means forretarding the action of said valve moving means.

i 13. In a compressor, the combination with high and low pressurecylinders, ofv a throttling device for the suction of the low pressurecylinder, means for moving the same under a predetermined terminalpressure, a relief valve for the high pressure cylinder opening to theatmosphere, said relief valve being, normally held to its seat byterminal pressure, a second valve adapted on movementtocut off theterminal pressure from said relief valve and apply a lower pressure tothe same, means connected to the moving means of said low pressurethrottling device for moving said second valve, and means for retardingthe action of said valve moving means j 14. In anjair compressonthecombination with pumping .mechanism, of unloading means actuated bypredetermined terminal pressure for cutting off the ingress of a1r tothe pumping mechanlsm, and means operated by, butacting subsequent tothe opera-.

tion of said unloading means, for permitting the discharge of air fromthe pumping mechanism to the atmosphere whereby the discharge of airthrough the discharge means to the atmosphere is deferred until afterthe compression of a substantial amount of the air remaining in thecompressor. v 1 p f 15. In an air compressor, the combination with highand low pressure cylinders, of an unloading valve for the low pressurecylinder, a relief valve forthe high pressure cylinder, means dependentupon a predetermined terminal pressure for moving said unloading valve,and means dependent upon said terminal pressure, but operated subsequentby an appreciable interval to the operation of said unloading valve, foropening said high pressure relief valve.

16. In a compressor the combination with an unloading valve, of acontrolling device having valve means to control said unloading valve,said valve means being adapted to be moved when a predetermined terminalpressure is reached, and means for restoring said valve means dependenton the conjoint action of a valve controlling spring, the terminalpressure and the pressure of a low pressure space of the compressor.

17. In a multiple stage compressor the combination with an unloadingvalve controlling the suction of the low pressure cylinder, of acontrolling device having valve means to control said unloading valve,said valve being adapted to be moved when a predetermined receiverpressure is reached, and means for restoring said valve means dependenton the conjoint action of the receiver pressure, the intercoolerpressure and a valve controlling spring.

18. In a compressor the combination with an unloading device forreducing the inlet pressure, of a valve for the discharge end, thelatter normally held closed, means dependent on an increase in receiverpressure to a predetermined point to control said unloading valve toreduce the inlet pressure and to open said relief valve, and means toretard the opening of the latter to follow the reduction in inletpressure.

19. In a compressor the combination with high and low pressurecylinders, of a throttling device for the suction of the low pressurecylinder, a relief valve for the high pressure cylinder, pressureresponsive means responsive to a predetermined terminal pressure,connections between said pressure responsive means and said throttlingdevice to operate the same, and connections between said pressureresponsive means and said relief valve to operate the latter but toretard the operation of the latter to cause the same to occursubsequently to the operation of the throttling device.

20. In an air compressor the combination with pumping mechanism, ofunloading means actuated by predetermined pressure for cutting off theingress of air to the pumping mechanism, relief means for the pumpingmechanism, and connections between the {unloading means and the reliefmeans to cause the operation of the latter to occur subsequently to theoperation of the former.

21. In a regulator for fluid compressors, in combination, a compressor,its receiver, a fluid operated relief valve mechanism, a fluid operatedintake closing valve, means for admitting fluid to operate said valvesat a predetermined receiver pressure, and means for delaying the actionof said fluid in operating said relief valve mechanism.

7 22. In a regulator for fluid compressors,

in combination, a compressor, its receiver, a fluid operated reliefvalve mechanlsm, a fluid operated mtake closing valve, means foradmitting fluid to operate said valves at a predetermined receiverpressure, and adjustable means for delaying the action of said fluid inoperating said relief valve mechanism.

28. In a regulator for fluid compressors, in combination, a compressor,its receiver, a fluid operated discharge line unloading valve mechanism,a fluid operated intake closing valve, means for admitting fluid tooperate said valves at a predetermined receiver pressure, and means fordelaying theaction of said fluid in operating said discharge lineunloading valve mechanism.

24. In a regulator for fluid compressors, in combination, a compressor,its receiver, a fluid operated discharge line unloading valve mechanism,a fluid operated intake closing valve, means for admitting fluid tooperate said valves at a predetermined receiver pressure, and adjustablemeans for delaying the action of said fluid in operating said dischargeline unloading valve mechanism.

In testimony whereof, l have signed my name to this specification, inthe presence of two subscribing Witnesses.

WADE H. WINEMAN. Witnesses:

FRANK A. HALLEGK, ALBERT F. PIPENHAGEN,

mullet eat this patent may be obtained for, five cents each, byaddressing the Commissioner at lt'atenta,

men, we W

